Optical wavelength division multiplexing (WDM) transmitters and receivers are used in optical transmission networks for transmitting large volumes of data. Optical transmitters and receivers comprise at least one optical multiplexer and one optical de-multiplexer, respectively. The optical multiplexer of a WDM transmitter has a plurality of channel input ports; optical channel signals of these input ports be combined into one multi-wavelength WDM signal for output. The optical de-multiplexer of a WDM receiver has a WDM input port to receive a multi-wavelength WDM input. The de-multiplexer splits the optical WDM reception signal into the individual channel signals and feeds each of these to an allocated channel output port.
Optical transceivers comprise both transmitter and receiver units. An integrated multi-wavelength WDM transceiver is a transceiver in a compact platform that allows multiple streams of data to be simultaneously placed on a single physical input and output (I/O) port using multiple optical WDM wavelengths from an array of lasers operated at the optical WDM wavelengths. Existing photonic transceiver architectures consist of optical transmit and receive paths physically isolated/separated such that when an optical link has to be formed between the transmit and receive path, it is necessarily an external optical link to the module (or in the case of photonic integrated circuit (PIC) based transceivers, external to the PIC). The problem with these transceiver architectures is that calibration and functional verification of the individual transmit and receive sections is limited to solutions that require a physical optical connection to be made external to the unit. Moreover, when the transceiver needs to be set to “normal” operation mode, this external connection has to be physically disconnected.
Descriptions of certain details and implementations follow, including a description of the figures, which may depict some or all of the embodiments described below, as well as discussing other potential embodiments or implementations of the inventive concepts presented herein. An overview of embodiments of the disclosure is provided below, followed by a more detailed description with reference to the drawings.